DuPont™ ISCEON® 9 SeriesREFRIGERANTS

Technical Information

ART- 44 (MO79-EU)

Retrofit Guidelines forDuPont™ ISCEON® MO79 (R-422A)

Refrigerant

Retrofit Guidelines for

DuPont™ ISCEON® MO79 Refrigerant

Table of Contents

Page

Introduction 1

Summary - Steps to Retrofit 1

Important Safety Information 1

Flammability 2

General Retrofit Information 2

Lubricant 2

Filter Drier 2

Elastomeric Seals/ Gaskets etc. 2

System Modifications 3

System Superheat 3

System Oil Management 3

Systems with Capillary Tube expansion devices 3

Refrigerant Recovery Information 3

Expected Performance After Retrofit 4

Detailed Retrofit Procedure for R22 Systems to ISCEON® MO79 4

Pressure-Temperature Charts 7

How to Read the Pressure/Temperature Tables 7

How to Determine Suction Pressure, Superheat, and Subcool 7

Retrofit Checklist for conversion of R22, R502, R402A, R408A (and other refrigerant) toISCEON® MO79 8

System Data Sheet 10

Physical property comparison 11

Composition of ISCEON® MO79 11

Appendix

(PT Charts ) 12

3

Introduction

DuPont™ ISCEON® MO79 (R-422A) is a non-ozone-

depleting HFC Refrigerant designed to replace R22

containing refrigerants used in R502 technology equipment

(e.g. R402A, R408A and others) in existing direct expansion

(DX) medium- and low-temperature refrigeration systems. It

is also recommended as a replacement for R22 in low

temperature DX refrigeration systems where either additional

system cooling capacity is required or in close-coupled

systems where compressor discharge temperature control is

not used. (In these cases check that system design

pressures will be adequate for ISCEON® MO79)

Field experience has shown that ISCEON® MO79 provides

performance that meets customer requirements in most

properly retrofitted systems. ISCEON® MO79 provides

similar cooling capacity and energy efficiency to R502 in

most systems. Actual performance depends on system

design and operating conditions.

ISCEON® MO79 is compatible with traditional and new

lubricants; in most cases no change of lubricant type

during retrofit is required. Oil return is determined by a

number of operating and design conditions – in some

systems with complex piping configurations or liquid

reservoirs on the low pressure side, POE may need to be

added. Minor equipment modifications (e.g., seal

replacement) or expansion device adjustments may be

required in some applications. Systems using ISCEON®

MO79 are easy to service. For most systems, should a

refrigerant loss occur, the charge can be completed

without the need to remove any residual refrigerant, and

the system will then operate normally. The cause of the

refrigerant loss should be investigated and corrected as

soon as is possible.

Note: When servicing critically charged systems, all of the

refrigerant charge should be removed. This is the same

practice recommended for all other refrigerants in critically

charged systems.

General Considerations

The use of ISCEON® MO79 in the EU and EEA member

countries is regulated under the terms of the Regulation

842/2006 (known as the “F Gas Regulation”), which

requires regular leakage testing for systems using the

designated substances. ISCEON® MO79 (R422A) is

listed in the European Standard EN 378:2008

(Refrigerating and Heat Pump Systems – Safety and

Environmental Requirements). Part 4 of this standard

relates to retrofit activities.

Summary - Steps to RetrofitThe following provides a summary of the basic retrofit steps

for ISCEON® MO79.

(Detailed discussion of each step is provided in this bulletin.)

1. Establish baseline performance with existing refrigerant.

(See retrofit checklist (attached))

2. Remove all the old (R22 containing) refrigerant from the

system into a recovery cylinder. Weigh the amount

removed.

3. Replace the filter drier and critical elastomeric

seals/gaskets.

4. Evacuate system and check for leaks.

5. Charge with ISCEON® MO79.

• Remove liquid only from charging cylinder.

• The initial charge amount should be lower than the

standard amount of old refrigerant. (For the expected

charge sizes for the principal R502 technology, R-22

containing refrigerants see Table 2)

6. Start up system, adjust charge size (unless liquid

receiver or TXV present) to achieve optimum

superheat.

7. Monitor oil levels in compressor. Add oil as required to

maintain proper levels

8. Label system showing the refrigerant (and any

replacement lubricant) used. Update system log-book.

Retrofit Complete

Important Safety Information

Like CFCs and HCFCs, ISCEON® 9 Series refrigerants are

safe to use when handled properly. However, any refrigerant

can cause injury or even death when mishandled. Please

review the following guidelines before using any refrigerant.

• Do not work in high concentrations of refrigerant vapors.

Always maintain adequate ventilation in the work area. Do

not breathe vapors. Do not breathe lubricant mists from

leaking systems. Ventilate the area well after any leak

before attempting to repair equipment.

4

• Do not use handheld leak detectors to check for

breathable air in enclosed working spaces. These

detectors are not designed to determine if the air is safe to

breathe. Use oxygen monitors to ensure adequate oxygen

is available to sustain life.

• Do not use flames or halide torches to search for leaks.

Open flames (eg. Halide detection torches, or brazing

torches) can release large quantities of acidic compounds

in the presence of all refrigerants, and these compounds

can be hazardous. Halide torches are not effective as leak

detectors for HFC refrigerants; they detect the presence of

Chlorine, which is not present in ISCEON® MO79, and

consequently, these detectors will not detect the presence

of this refrigerant. Use an electronic leak detector

designed to find the refrigerants you are using.

If you detect a visible change in the size or color of a flame

when using brazing torches to repair equipment, stop work

immediately and leave the area. Ventilate the work area

well and stop any refrigerant leaks before resuming work.

These flame effects may be an indication of very high

refrigerant concentrations, and continuing to work without

adequate ventilation may result in injury or death.

Note: Any refrigerant can be hazardous if used improperly.

Hazards include liquid or vapor under pressure, and frostbite

from the escaping liquid.

Overexposure to high concentrations of refrigerant vapor can

cause asphyxiation and cardiac arrest. Please read all safety

information before handling any refrigerant.

Refer to the ISCEON® MO79 Material Safety Data Sheet

(MSDS) for more specific safety information. .DuPont Safety

Bulletin AS-1 also gives additional information for safe

handling of refrigerants.

Flammability

ISCEON® MO79 is non-flammable in air under normal

conditions. However, this product when mixed with high

concentrations of air or oxygen under elevated pressure can

become combustible in the presence of an ignition source.

This product should not be mixed with air to check for

system leaks.

General Retrofit Information

Lubricants

Lubricant selection is based on many factors, including

compressor wear characteristics, material compatibility, and

lubricant/refrigerant solubility (which can affect oil return to

the compressor). ISCEON® MO79 is compatible with

traditional and new lubricants – in most retrofit situations with

direct expansion systems no change of oil type is required.

Field experience has shown that ISCEON® MO79 will

work successfully with the existing mineral (or alkyl-

benzene) oil in most DX systems. In systems where oil

return is a potential concern, such as systems where the

suction line accumulator acts as a low pressure receiver,

replacement of all, or part (~30%) of the compressor oil

charge with an OEM approved polyol ester oil is

recommended.

Filter Drier

Change the filter drier during the retrofit. This is a routine

system maintenance practice. There are two types of filter

driers commonly used, solid core and loose filled. Replace

the drier with the same type currently in use in the system.

The drier label will show which refrigerants can be used with

that drier. Select a drier specified to work with HFC

refrigerants. (Many driers sold today are “universal” – they

will work with most fluorocarbon refrigerants.)

Elastomeric Seals/ Gaskets etc.

R22 containing refrigerant blends (and to a greater extent

R22), interact relatively strongly with many elastomers

causing significant swelling and often, over time, a

measurable increase in hardness, etc. ISCEON® MO79

does not have such a strong effect on those elastomers

commonly used in seals in refrigeration systems. A

consequence of this is that, when replacing R22 containing

blends (and, to a greater extent, R22) with ISCEON® MO79

in a system retrofit, it is possible for leaks to occur at

Elastomeric seals that are exposed to the refrigerant. (This is

not a problem attributable to the use of ISCEON® MO79.

Such seal leaks have been reported when replacing R22

based refrigerants with other HFC refrigerants such as

R407C or R404A.) Leaks do not occur in every system

retrofitted and, in practice, it is difficult to predict whether

such leaks will occur. (As a rule of thumb the older the

system, the higher the probability that leaks will be observed

after a retrofit.)

5

As a consequence it is recommended to change any

system-critical seals (those which would require removal of

the refrigerant charge to allow seal replacement e.g., liquid

receiver, liquid sight glasses, etc.) as a matter of course

during the retrofit and to have spare seals for other

components available during restart of the system. A

rigorous leak check regime pre- and post- retrofit will

minimize any refrigerant losses. All seals should be checked

including manual valves, schrader valves, solenoid valves,

sight glasses, electrical cable sealing grommets (on

compressors), mechanical seals on open drive compressors,

etc. Obviously any seals found to be leaking before the

retrofit takes place should be replaced during the retrofit.

System Modifications

The compositions of the ISCEON® MO79 refrigerant has

been selected to provide performance comparable R502 in

terms of both capacity and energy efficiency. As a result,

minimal system modifications are anticipated when

retrofitting.

ISCEON® MO79 is a near-azeotrope. The vapor

composition in the refrigerant cylinder is different from the

liquid composition. For this reason, ISCEON® MO79 should

be transferred from the container from the liquid phase

during system charging (or when transferring from one

container to another).

In general, ISCEON® MO79 refrigerant is not recommended

for use in centrifugal compressor systems or for chillers with

flooded evaporators. Direct expansion systems with low

pressure receivers may be retrofitted using ISCEON® MO79

but a single oil change to a POE oil of the same viscosity as

the original oil type is required to ensure adequate oil

management for this system configuration.

Note: ISCEON® MO79 should not be mixed with other

refrigerants or additives that have not been clearly specified

by DuPont or the system equipment manufacturer. Mixing

this refrigerant with CFC or HCFC refrigerants, or mixing two

different alternative refrigerants, may have an adverse effect

on system performance. “Topping off” a CFC or HCFC

refrigerant with any Suva® or ISCEON® 9 Series refrigerant

is strictly not recommended.

System Superheat

Desired system performance after a retrofit with DuPont™

ISCEON® MO79 requires correct setting of the system

superheat. This is discussed in the detailed retrofit

procedures given below.

System Oil Management

In many situations, systems retrofitted with ISCEON® MO79

have operated routinely using the mineral oil or Alkyl

benzene that was used with the original HCFC refrigerant.

With complex systems, in a small number of cases, the oil

may not return consistently to the compressor.

It is important that oil levels in the compressors be monitored

during initial operation with the ISCEON® MO79. If the oil

level falls below the minimum allowed, top up the oil to the

minimum level with the existing oil type. Do not fill to

maximum as the level may rise again.

Should the oil level fall continuously, or suffer large

oscillations during an operating cycle, addition of POE

lubricant has proven effective in restoring adequate oil return

rates. POE lubricant should be progressively added to the

system. An initial addition of 10-30% (of the total oil charge)

should be made. This should be followed by further small

increments until the oil level returns to normal.

It is important to ensure that, when adding POE oil to the

system, the oil level (immediately after addition) is kept

below the system mid-point (e.g. mid-sight glass) oil level.

It is also important to keep accurate records of how much oil

is added to avoid over-filling.

Systems with Capillary Tube expansiondevice

In general it is not necessary to change the capillary tube in

the refrigerant circuit. Experience has shown that capillary

tubes used in R502 and similar systems give good

performance when the system is retrofitted to use ISCEON®

MO79. In these systems setting of the compressor

suction superheat is made by adjusting the refrigerant

charge quantity in the system.

Refrigerant Recovery Information

Most recovery or recycle equipment used for R502, R22 or

R22 containing blends, can be used for ISCEON® MO79.

Use standard procedures to avoid cross contamination when

switching from one refrigerant to another. Most recovery or

recycle machines can use the same compressor oil that was

used for the HCFC refrigerant. However, some modifications

may be necessary, such as a different kind of drier or a

different moisture indicator. Consult the equipment

manufacturer for specific recommendations.

6

Expected Performance After Retrofit

Table 1 shows approximate system performance changes

following a retrofit and are general guidelines for system

behavior. These values are based on thermodynamic

property data; and assume equal compressor efficiency.

Cooling capacity and energy efficiency depend greatly on

system design, operating conditions and the actual condition

of the equipment. ISCEON® MO79 provides similar cooling

capacity and energy efficiency to R22 containing blends in

most systems while operating at significantly lower

compressor discharge temperature. Actual performance

depends on system design and operating conditions.

Table 1ISCEON

®MO79 Performance Compared to R22, R502, Suva

®HP80 and Suva

®408 in Low Temperature refrigeration

systems

Performance with subcooling based on thermocycle calculations and do not include heat tr ansfer effects

RefrigerationLow Temperature

–35°C evaporator, 40°C condenser, 8K evaporator superheat, 18°C return gas, 5K subcooling

Difference vsR502

Difference vsSuva HP80

(R402A)

Difference vsR408A

Difference vsR22

Difference vsR407A

Discharge Temperature (with demand cooling) -8 K -8 K -8 K -8 K -8 K

Discharge Temperature (without demand cooling) -17 K -18 K -31 K -64 K -34 K

Discharge Pressure (bar) 1.7 -1.0 1.4 3.0 0.9

Cooling Capacity (with demand cooling) -2% -9% 5% 28% 18%

C.O.P. (with demand cooling) -3% 1% 5% 16% 9%

“+” represents an increase and “–“ represents a decrease for ISCEON®

MO79 vs. the other refrigerants.R22 assumes demand cooling with discharge temperature controlled at 125ºC

Table 2

Refrigerant Charge Amount Recommendations for Retrofit to ISCEON® MO79

Approximate ApproximateInitial Charge Final Charge

R22 85% 95%R502 85% 95%

R402A (HP80) 90% 100%R408A 90% 105%

Note: These values apply provided no changes to mechanical components of the system (which could significantly affect the

system’s internal volumetric capacity) will be made during the retrofit.

7

Detailed Retrofit Procedure for R22 inDirect Expansion Medium and LowTemperature Refrigeration Systems,Residential and Commercial Air-Conditioning

(Refer to the retrofit checklists on p. 8 and 9of this bulletin)

1. Establish baseline performance before the retrofit.

Collect system performance data while the previous

refrigerant is in the system. Check for correct refrigerant

charge and operating conditions. The baseline data of

temperatures and pressures at various points in the system

(evaporator, condenser, compressor suction and discharge

and calculation of superheat and subcool.) at normal

operating conditions will be useful when optimizing operation

of the system with the ISCEON®

MO79. A System Data

Sheet is included at the back of this bulletin to record

baseline data.

2. Remove the existing refrigerant from the system

into a recovery cylinder. The existing charge should be

removed from the system and collected in a recovery

cylinder using a recovery device capable of pulling 10–15 in

Hg vacuum (50–65) kPa absolute). If the recommended

charge size for the system is not known, weigh the amount

of refrigerant removed. The initial quantity of ISCEON®

MO79 to charge to the system can be estimated from this

amount. (See step 5). Ensure that any residual refrigerant

dissolved in the compressor oil is removed by holding the

system under vacuum. Break the vacuum with dry nitrogen.

3. Replace the filter drier and critical elastomeric

seals/gaskets etc

It is routine practice to replace the filter drier during system

maintenance. Replacement filter driers are available that are

compatible with ISCEON® MO79.

While the system is empty, check and replace any

elastomeric seals that may be near the end of their

serviceable life. Even if they were not previously leaking, the

change of swell characteristics when changing to any new

refrigerant (e.g., R22 containing refrigerant to any HFC

refrigerant) and the general disturbance to the system may

cause worn seals to leak after retrofit. Although, in general,

the same seal materials can be used with ISCEON® MO79

(refer to Compatibility Tables in the DuPont PUSH bulletin

#K-10927) it has been observed as with other HFC based

refrigerants that shrinkage of the original seal may occur

after conversion causing refrigerant leakage (refer to the

DuPont bulletin on HFC Compatibility with Elastomeric Seals

#K-17335). Critical components commonly affected are

Schrader core seals, liquid level receiver gaskets, solenoid

valves, ball valves and flange seals but all external seals in

contact with the refrigerant should be viewed as a potential

leak source post retrofit. Field experience has shown that the

older the system, the greater the likelihood of seal and

gasket leaks. It is recommended to change any system

critical seals (e.g., those which require removal of the

refrigerant charge to allow seal replacement e.g., liquid

receiver, condenser system) as a matter of course and to

have spare seals for other components available during the

retrofit should any seal failure occur Schrader valves can

generally be changed in-situ, under pressure, using a special

tool, and thus are not considered to be system critical. A

rigorous leak check regime pre and post retrofit will minimize

any refrigerant losses.

4. Evacuate system and check for leaks. Use normal

service practices. To remove air or other non-

condensables and any residual moisture from the system,

evacuate the system to near full vacuum (29.9 in Hg vacuum

[500 microns] or less than 0.1 kPa absolute), isolate the

vacuum pump from the system and observe the vacuum

reading. If the system does not maintain vacuum it is an

indication that there might be a leak. Pressurise the system

with nitrogen taking care not to exceed the system design

maximum pressure and check for leaks. Do not use mixtures

of air and refrigerant under pressure to check for leaks;

these mixtures can be combustible. After leak checking with

Nitrogen remove residual Nitrogen using a vacuum pump.

5 Charge with ISCEON® MO79. Remove liquid only

from charging cylinder. (If the cylinder does not have a valve

with a dip-tube invert the cylinder so that the valve is

underneath the cylinder). The proper cylinder position for

liquid removal is often indicated by arrows on the cylinder

and cylinder box. Once Liquid is removed from the cylinder,

the refrigerant can be allowed to enter the refrigeration

system as liquid or vapor as desired. Use the manifold

gauges or a throttling valve to flash the liquid to vapor if

required.

WARNING: Do not charge liquid refrigerant into the

compressor. This will cause serious irreversible

damage!

In general, the refrigeration system will require less weight of

the ISCEON® MO79 than of the original R22 charge,

8

although some will require slightly more (See table 2). The

optimum charge will vary depending on the system design

and operating conditions.

Note: For systems with a liquid refrigerant receiver charge

the system to the normal refrigerant level in the receiver. The

values given in table 2 apply provided no changes to

mechanical components of the system (which could

significantly affect the system’s internal volumetric capacity)

will be made during the retrofit.

6. Start up system, adjust charge size (for systems

without a liquid receiver).

Start the system and let conditions stabilize. If the system is

undercharged (as indicated by the level of superheat at the

evaporator exit, or by the amount of sub-cool at the

condenser exit) add more ISCEON® MO79 in small amounts

(still by transferring as liquid from the charging cylinder) until

the system conditions reach the desired level. See the

pressure-temperature charts in this bulletin to compare

pressures and temperatures in order to calculate superheat

or sub-cooling for the refrigerant you are using. Sight

glasses in the liquid line can be used in most cases as a

guide to system charge, but correct system charge must be

determined by measuring system operating conditions

(discharge and suction pressures, suction line temperature,

compressor motor amps, superheat, etc.). Attempting to

charge until the sight glass is “free of bubbles” may result in

overcharging the refrigerant. Please read “How to Determine

Suction Pressure, Superheat and Subcool.”

Ensuring that the correct compressor suction superheat

is set is very important for reliable system operation with

ISCEON® MO79. Experience has shown that superheat (at

the compressor inlet) for ISCEON® MO79 should be the

same as for the refrigerant being replaced.

WARNING: Liquid refrigerant entering the compressor at

any time during system operation can lead to

compressor oil level problems and rapid compressor

failure.

7. Monitor oil levels.

During initial operation of the system it is very important

to monitor the level of oil in the compressor (or

compressor oil management system) to verify that oil is

returning to the compressor in an adequate manner.

• If the oil level falls below the minimum allowed level,

top up to the minimum level with the existing oil type.

Do not fill to the maximum level as the level may rise

again.

• Should the oil return appear to be erratic as

evidenced by large swings in oil level during the

refrigeration system cycle it is recommended that

some of the oil be removed from the system and

replaced with POE oil. Replacement of up to 30% of

the oil with POE will help to restore oil return stability.

The exact amount of oil to be changed will depend

on the system itself (evaporating temperatures,

physical geometry, etc.)

• POE lubricant should be progressively added to the

system. An initial addition of 10 – 20% (of the total oil

charge) should be made. This should be followed by

small increments until the oil level returns to normal

consistently throughout the refrigeration system

operating cycle.

• It is important to ensure that, when adding POE oil to

the system, the oil level (immediately after addition)

is kept below the system mid-point (e.g. mid-sight

glass) oil level.

8. Label the system to clearly and permanently show the

refrigerant in the system and any oil(s) present in the

system. It is most important that the change in

refrigerant and any other component (including

lubricating oil) changes be registered in the system

documentation (log book).

IMPORTANT: Thoroughly leak check the system. As

mentioned in step 3 it is possible that refrigerant

leakage can occur during or immediately after a

retrofit. Experience has shown that some leaks will

not appear until after the new refrigerant has been

charged to the system. Pay particular attention to

Schrader valve core seals, solenoid valves and ball

valve stems on the liquid high-pressure side.

9

Pressure/Temperature Charts

How to Read the Pressure/Temperature Chart

The following pages contain pressure/temperature charts for

the refrigerants discussed in this bulletin. Three

temperatures are shown at a given pressure:

• Saturated Liquid Temperature (Bubble Point)—In the

condenser, this is the temperature at which the last bit of

vapor has condensed. Below this temperature, the

refrigerant will be subcooled liquid. This temperature

should also be used when determining the

pressure/temperature value of product stored in a

refrigerant cylinder.

• Saturated Vapor Temperature (Dew Point)—In the

evaporator, this is the temperature at which the last drop

of liquid has just boiled. Above this temperature, the

refrigerant will be superheated vapor.

• Average Coil Temperature (for ISCEON® MO79)—The

evaporator and condenser will perform as if it is operating

at this constant temperature. It is an average of the bubble

and dew point temperatures determined from either the

suction or condenser pressure. Use this average

temperature to compare coil temperatures with the

refrigerant you are replacing. Note: this is an

approximation of the average temperature for low glide

refrigerants.

How to Determine Suction Pressure,Superheat, and Subcool

Suction Pressure

Determine the expected evaporator temperature using the

R22 containing refrigerant (from the baseline data you

collected prior to the retrofit). Find the same expected

evaporator temperature in the Average Coil Temperature

column for ISCEON® MO79. Note the corresponding

pressure for this temperature. This is the approximate

suction pressure at which the system should operate.

Superheat

Using the saturated vapor pressure tables for ISCEON®

MO79, determine the saturated vapor temperature (dew

point) for the measured suction pressure. Measure the

temperature at the compressor inlet (suction) and subtract

the previously determined dew point temperature for

ISCEON MO79 to give the amount of vapor superheat.

Subcool

Using the saturated liquid pressure tables for ISCEON®

MO79, determine the saturated liquid temperature (bubble

point) for the measured condensing pressure (usually the

high-side pressure). Measure the refrigerant liquid line

temperature and subtract it from the previously determined

bubble point temperature for ISCEON® MO79 to give the

amount of liquid subcool.

10

Retrofit Checklists for Converting CFC or HCFC Systems to DuPont™ ISCEON® MO79

Retrofit Guidelines forDuPont™ ISCEON® MO79 Refrigerant

Retrofit Check List: 1) Pre- and Post- Retrofit Checks

Pre-Retrofit

Advance Preparation for Retrofit

1 Ensure the Retrofit Procedure has been read

Clarify any doubts with DuPont Technical Services

2 Check Service History log-book

Recent refrigerant additions might signify system leaks

Is current system design in agreement with log-book?

3 Leak check system

If leaks found schedule repair

4 Check compressor oil management system design

If no oil separator present oil level observation needed after retrofit

5 System performance check: complete data sheet

See Retrofit procedure p.10

If obvious performance problem: Correct before retrofit (or plan to do it during retrofit)

6 Identify system critical elastomeric seals

See Retrofit Guidelines p.2

7 Check Compressor oil condition

If doubtful schedule change

8 Ensure all needed materials will be available

Seals, filter cores, etc.

Recovery cylinder(s) Recovery machine, vacuum pump, Nitrogen

Technical data: Retrofit Guidelines, PT data (Slide rules, etc.)

Post-Retrofit

Verification of system performance and integrity

24 hrs 48 hrs 72hrs 1 week

1 Observe compressor oil level

Correct if needed (see Guidelines p 6)

2 Measure Performance Data

Use Data Sheet

3 Carry out Leak check

Correct any leaks found

Complete

CheckComplete

Check

11

Retrofit Guidelines forDuPont™ ISCEON® MO79 Refrigerant

Retrofit Check List: 2) Retrofit Progress Checks

Retrofit Steps

1 Recover old refrigerant using good refrigeration practice

Use dedicated recovery cylinder(s)

Weigh the recovered refrigerant

De-gas the compressor oil using a vacuum pump

2 Break the vacuum using dry nitrogen

Minimise ingress of moist air into the system

4 Change necessary mechanical components

Filter/dryer

Identified system critical elastomeric seals

Replace oil if needed

5 Evacuate system. Hold under vacuum.

To remove moisture.

Early indication of leaks (if vacuum does not hold)

6 If indication of leak pressurise with Nitrogen.

Locate leak(s). De-pressurise and correct

Evacuate system. Hold under vacuum

7 Charge with ISCEON®MO79 from liquid phase

a) If system receiver - to normal level

b) If no receiver - initial 90% of R22 charge (See text for values for other refrigerants)

8 Start system, measure performance data (See data sheet)

Adjust refrigerant charge if needed

Adjust superheat setting if needed

10 Check Compressor oil levels

Adjust if necessary

11 Re-check system for refrigerant leaks

12 Label System

Refrigerant (and any added/changed oil)

Update log-book

CheckComplete

12

System Data Sheet

Type of System/Location: _________________________________________________________________________Equipment Mfg.:_______________________________________ Compressor Mfg.:______________________________Model No.:_______________________________________ Model No.:____________________________________Serial No.:_______________________________________ Serial No.:____________________________________Date of Manufacture_______________________________ Date of manufacture____________________________Original Refrigerant Charge Size:__________________________ Lubricant Type:____________________________Lubricant Charge Size:__________________________________ Drier Mfg.:____________________________________

Drier Type (check one): Model No.:_________________________ Loose Fill:________Solid Core:___________________

Condenser Cooling Medium (air/water): _________________________________________________________________

Expansion Device (check one): Capillary Tube: _________Expansion Valve: _______

If Expansion valve: Manufacturer: _____________________________ Model No:_______________________________

Control/Set Point: ________________ Location of Sensor: __________________________________________________

Other System Controls (ex.: head press control),

Describe:_____________________________________________________________________

(circle units used where applicable)

Date/Time

Refrigerant

Charge Size (kg)

Ambient Temp. (°C)

Compressor:

Suction T (°C)

Suction P (kPa)

Discharge T (°C)

Discharge P (kPa/)

Evaporator:

Coil Air/H2O In T (°C)

Coil Air/H2O Out T (°C)

Operating Service Temperature) (°C)

Condenser:

Coil Air/H2O In T (°C)

Coil Air/H2O Out T (°C)

Superheat and Sub-Cool (derived values)

Refrigerant T at Superheat Ctl. Pt (°C)

Calculated Superheat (K)

Exp. Device Inlet T (°C)

Calculated sub-cool (K)

Motor Amps (if pack: total)

13

Table 3

Physical Properties of DuPont™ ISCEON® MO79

Physical Property Unit ISCEON®

MO79 R-22 R-502

Boiling Point (1 atm.) °C –47 –41 –45

Pressure at 25°C (77°F) kPa abs 1274 1041 1162

Density at 25°C (77°F) kg/m3

1136 1193 1217

Satd. Vapor at 25°C (77°F) kg/m3

74.3 44.9 67.3

Ozone Depletion Potential CFC11 = 1.0 0 0.05 0.23Global Warming Potential CO2 = 1 2530 1700 5494

Table 4

Composition of ISCEON® MO79 (Wt. %)

HFC125 HFC134a isobutane

ISCEON MO79 85.1 11.5 3.4

14

Appendix

Table 5

Pressure – Temperature Chart (SI Units): R22, R502 and ISCEON® MO79

Pressure Temperature (ºC)(bar(g)) R22 ISCEON®MO79 R502

Sat Liq Sat Vap. Ave. Coil

–0.7 –64 –69 –66 –67 –68–0.6 –59 –64 –61 –63 –63–0.5 –55 –60 –57 –59 –59–0.4 –51 –57 –54 –55 –56–0.3 –48 –54 –51 –53 –53

–0.2 –46 –51 –49 –50 –50–0.1 –43 –49 –46 –48 –48

0 –41 –47 –44 –46 –45

0.1 –39 –45 –42 –44 –430.2 –37 –43 –41 –42 –41

0.3 –35 –41 –39 –40 –400.4 –34 –40 –37 –38 –380.5 –32 –38 –36 –37 –360.6 –31 –37 –34 –35 –350.7 –29 –35 –33 –34 –33

0.8 –28 –34 –32 –33 –32

0.9 –26 –33 –30 –31 –311 –25 –31 –29 –30 –29

1.1 –24 –30 –28 –29 –28

1.2 –23 –29 –27 –28 –27

1.3 –22 –28 –26 –27 –261.4 –21 –27 –25 –26 –251.5 –20 –26 –24 –25 –24

1.6 –18 –25 –23 –24 –231.7 –17 –24 –22 –23 –22

1.8 –17 –23 –21 –22 –211.9 –16 –22 –20 –21 –20

2 –15 –21 –19 –20 –192.1 –14 –20 –18 –19 –182.2 –13 –19 –17 –18 –17

2.3 –12 –18 –17 –18 –16

2.4 –11 –18 –16 –17 –152.5 –10 –17 –15 –16 –142.6 –10 –16 –14 –15 –14

2.7 –9 –15 –13 –14 –13

2.8 –8 –15 –13 –14 –122.9 –7 –14 –12 –13 –11

3 –7 –13 –11 –12 –113.1 –6 –12 –11 –12 –103.2 –5 –12 –10 –11 –9

3.3 –4 –11 –9 –10 –83.4 –4 –10 –9 –9 –8

Pressure Temperature (ºC)(bar(g)) R22 ISCEON®MO79 R502

Sat Liq Sat Vap. Ave. Coil

3.5 –3 –10 –8 –9 –7

3.6 –2 –9 –7 –8 –63.7 –2 –8 –7 –8 –6

3.8 –1 –8 –6 –7 –53.9 0 –7 –5 –6 –4

4 0 –7 –5 –6 –44.2 1 –5 –4 –5 –34.4 3 –4 –3 –3 –1

4.6 4 –3 –1 –2 0

4.8 5 –2 0 –1 15 6 –1 1 0 2

5.2 7 0 2 1 3

5.4 8 1 3 2 4

5.6 9 2 4 3 55.8 10 3 5 4 6

6 11 4 6 5 76.2 12 5 6 6 86.4 13 6 7 7 9

6.6 14 7 8 7 106.8 15 7 9 8 11

7 15 8 10 9 127.2 16 9 11 10 137.4 17 10 12 11 13

7.6 18 11 12 12 14

7.8 19 12 13 12 158 20 12 14 13 16

8.2 20 13 15 14 17

8.4 21 14 15 15 18

8.6 22 15 16 15 188.8 23 15 17 16 19

9 23 16 18 17 20

9.5 25 18 19 19 2210 27 19 21 20 23

10.5 29 21 23 22 2511 30 23 24 23 27

11.5 32 24 26 25 2812 33 26 27 26 30

12.5 35 27 28 28 31

13 36 29 30 29 3313.5 38 30 31 31 34

14 39 31 33 32 3614.5 40 33 34 33 37

15 42 34 35 34 38

15

Pressure Temperature (ºC)(bar(g)) R22 ISCEON®MO79 R502

Sat Liq Sat Vap. Ave. Coil

15.5 43 35 36 36 4016 44 36 37 37 41

16.5 46 37 39 38 4217 47 39 40 39 43

17.5 48 40 41 40 45

18 49 41 42 41 4618.5 50 42 43 43 47

19 51 43 44 44 4819.5 52 44 45 45 49

20 53 45 46 46 50

20.5 54 46 47 47 5121 56 47 48 48 52

21.5 57 48 49 49 53

22 58 49 50 50 5422.5 59 50 51 51 55

23 59 51 52 51 5623.5 60 52 53 52 57

24 61 53 54 53 5824.5 62 54 55 54 59

25 63 55 55 55 60

25.5 64 55 56 56 61

26 65 56 57 57 6226.5 66 57 58 58 63

27 67 58 59 58 6427.5 68 59 60 59 64

28 68 60 60 60 6528.5 69 60 61 61 66

29 70 61 62 61 67

29.5 71 62 63 62 6830 72 63 63 63 68

30.5 72 63 64 64 6931 73 64 65 64 70

31.5 74 65 65 65 7132 75 66 66 66 72

32.5 75 67 67 67 72

33 76 73

33.5 77 7434 78 74

34.5 78 75

Note: Saturated Liquid Temperature = Bubble Point

Saturated Vapor Temperature = Dew Point

16

Table 6

Pressure – Temperature Charts (SI Units): Suva®HP80 (R402A) and ISCEON®

MO79

Pressure Temperature (ºC)bar (g) ISCEON®ISCEON®ISCEON®Suva® Suva® Suva®

MO79 MO79 MO79 HP80 HP80 HP80Sat.Liq. Sat.Vap. Ave.Coil Sat.Liq. Sat. Vap. Ave.Coil

–0.7 –69 –66 –67 –72 –69 –70–0.6 –64 –61 –63 –67 –64 –66–0.5 –60 –57 –59 –63 –61 –62–0.4 –57 –54 –55 –59 –57 –58–0.3 –54 –51 –53 –56 –54 –55

–0.2 –51 –49 –50 –54 –52 –53–0.1 –49 –46 –48 –51 –49 –50

0 –47 –44 –46 –49 –47 –480.1 –45 –42 –44 –47 –45 –460.2 –43 –41 –42 –45 –43 –44

0.3 –41 –39 –40 –44 –42 –430.4 –40 –37 –38 –42 –40 –410.5 –38 –36 –37 –40 –39 –390.6 –37 –34 –35 –39 –37 –380.7 –35 –33 –34 –37 –36 –37

0.8 –34 –32 –33 –36 –34 –350.9 –33 –30 –31 –35 –33 –341 –31 –29 –30 –34 –32 –33

1.1 –30 –28 –29 –32 –31 –311.2 –29 –27 –28 –31 –30 –30

1.3 –28 –26 –27 –30 –28 –291.4 –27 –25 –26 –29 –27 –281.5 –26 –24 –25 –28 –26 –271.6 –25 –23 –24 –27 –25 –261.7 –24 –22 –23 –26 –24 –25

1.8 –23 –21 –22 –25 –23 –241.9 –22 –20 –21 –24 –23 –232 –21 –19 –20 –23 –22 –22

2.1 –20 –18 –19 –22 –21 –222.2 –19 –17 –18 –21 –20 –21

2.3 –18 –17 –18 –21 –19 –202.4 –18 –16 –17 –20 –18 –192.5 –17 –15 –16 –19 –18 –182.6 –16 –14 –15 –18 –17 –172.7 –15 –13 –14 –17 –16 –17

2.8 –15 –13 –14 –17 –15 –162.9 –14 –12 –13 –16 –15 –153 –13 –11 –12 –15 –14 –15

3.1 –12 –11 –12 –15 –13 –143.2 –12 –10 –11 –14 –12 –13

3.3 –11 –9 –10 –13 –12 –123.4 –10 –9 –9 –12 –11 –123.5 –10 –8 –9 –12 –10 –113.6 –9 –7 –8 –11 –10 –103.7 –8 –7 –8 –11 –9 –10

3.8 –8 –6 –7 –10 –9 –93.9 –7 –5 –6 –9 –8 –94 –7 –5 –6 –9 –7 –8

4.2 –5 –4 –5 –7 –6 –74.4 –4 –3 –3 –6 –5 –6

Pressure Temperature (ºC)bar (g)

ISCEON®ISCEON®ISCEON® Suva® Suva® Suva®

MO79 MO79 MO79 HP80 HP80 HP80Sat.Liq. Sat.Vap. Ave.Coil Sat.Liq. Sat. Vap. Ave.Coil

4.6 –3 –1 –2 –5 –4 –54.8 –2 0 –1 –4 –3 –45 –1 1 0 3 –2 1

5.2 0 2 1 –2 –1 –25.4 1 3 2 –1 0 –1

5.6 2 4 3 0 1 15.8 3 5 4 1 2 26 4 6 5 2 3 3

6.2 5 6 6 3 4 46.4 6 7 7 4 5 5

6.6 7 8 7 5 6 66.8 7 9 8 6 7 77 8 10 9 6 8 7

7.2 9 11 10 7 8 87.4 10 12 11 8 9 9

7.6 11 12 12 9 10 107.8 12 13 12 10 11 118 12 14 13 11 12 12

8.2 13 15 14 11 12 128.4 14 15 15 12 13 13

8.6 15 16 15 13 14 148.8 15 17 16 14 15 159 16 18 17 14 15 15

9.5 18 19 19 16 17 1710 19 21 20 19 20 20

10.5 21 23 22 21 22 2111 23 24 23 22 23 23

11.5 24 26 25 24 25 2412 26 27 26 25 26 26

12.5 27 28 28 27 28 27

13 29 30 29 28 29 2913.5 30 31 31 30 30 3014 31 33 32 31 32 31

14.5 33 34 33 32 33 3315 34 35 34 33 34 34

15.5 35 36 36 35 35 3516 36 37 37 36 37 36

16.5 37 39 38 37 38 3717 39 40 39 38 39 38

17.5 40 41 40 39 40 40

18 41 42 41 40 41 4118.5 42 43 43 41 42 4219 43 44 44 42 43 43

19.5 44 45 45 43 44 4420 45 46 46 44 45 45

20.5 46 47 47 45 46 4621 47 48 48 46 47 47

21.5 48 49 49 47 48 4822 49 50 50 48 49 49

22.5 50 51 51 49 50 50

17

Pressure Temperature (ºC)bar (g)

ISCEON®ISCEON®ISCEON® Suva® Suva® Suva®

MO79 MO79 MO79 HP80 HP80 HP80Sat.Liq. Sat.Vap. Ave.Coil Sat.Liq. Sat. Vap. Ave.Coil

23 51 52 51 50 51 5123.5 52 53 52 51 52 5124 53 54 53 52 53 5224.5 54 55 54 53 54 5325 55 55 55 54 54 54

25.5 55 56 56 55 55 5526 56 57 57 56 56 56

26.5 57 58 58 56 57 5727 58 59 58 57 58 57

27.5 59 60 59 58 59 58

28 60 60 60 59 59 5928.5 60 61 61 60 60 6029 61 62 61 60 61 61

29.5 62 63 62 61 62 6130 63 63 63 62 62 62

30.5 63 64 64 63 63 6331 64 65 64 63 64 64

31.5 65 65 65 64 65 6432 66 66 66 65 65 65

32.5 67 67 67 66 66 66

Note: Saturated Liquid Temperature = Bubble PointSaturated Vapor Temperature = Dew Point

18

Table 7

Pressure – Temperature Charts (SI Units): Suva®408 (R408A) and ISCEON®

MO79

Pressure Temperature ( C)

bar (g)

ISCEON®ISCEON®ISCEON® Suva® Suva® Suva®

MO79 MO79 MO79 408A 408A 408A

Sat. Liq. Sat. Vap. Av. Coil Sat. Liq. Sat. Vap Av. Coil

–0.7 –69 –66 –67 –67 –67 –67–0.6 –64 –61 –63 –62 –62 –62–0.5 –60 –57 –59 –58 –58 –58–0.4 –57 –54 –55 –55 –54 –55–0.3 –54 –51 –53 –52 –51 –52

–0.2 –51 –49 –50 –49 –49 –49–0.1 –49 –46 –48 –47 –46 –47

0 –47 –44 –46 –45 –44 –440.1 –45 –42 –44 –43 –42 –420.2 –43 –41 –42 –41 –40 –40

0.3 –41 –39 –40 –39 –38 –390.4 –40 –37 –38 –37 –37 –370.5 –38 –36 –37 –36 –35 –350.6 –37 –34 –35 –34 –34 –340.7 –35 –33 –34 –33 –32 –32

0.8 –34 –32 –33 –31 –31 –310.9 –33 –30 –31 –30 –30 –301 –31 –29 –30 –29 –28 –29

1.1 –30 –28 –29 –28 –27 –271.2 –29 –27 –28 –26 –26 –26

1.3 –28 –26 –27 –25 –25 –251.4 –27 –25 –26 –24 –24 –241.5 –26 –24 –25 –23 –23 –231.6 –25 –23 –24 –22 –22 –221.7 –24 –22 –23 –21 –21 –21

1.8 –23 –21 –22 –20 –20 –201.9 –22 –20 –21 –19 –19 –192 –21 –19 –20 –18 –18 –18

2.1 –20 –18 –19 –17 –17 –172.2 –19 –17 –18 –16 –16 –16

2.3 –18 –17 –18 –16 –15 –152.4 –18 –16 –17 –15 –14 –152.5 –17 –15 –16 –14 –14 –142.6 –16 –14 –15 –13 –13 –132.7 –15 –13 –14 –12 –12 –12

2.8 –15 –13 –14 –12 –11 –112.9 –14 –12 –13 –11 –11 –113 –13 –11 –12 –10 –10 –10

3.1 –12 –11 –12 –9 –9 –93.2 –12 –10 –11 –9 –8 –9

3.3 –11 –9 –10 –8 –8 –83.4 –10 –9 –9 –7 –7 –73.5 –10 –8 –9 –7 –6 –73.6 –9 –7 –8 –6 –6 –63.7 –8 –7 –8 –5 –5 –5

3.8 –8 –6 –7 –5 –4 –53.9 –7 –5 –6 –4 –4 –44 –7 –5 –6 –4 –3 –3

4.2 –5 –4 –5 –2 –2 –2

Pressure Temperature ( C)

bar (g)ISCEON®ISCEON®ISCEON® Suva® Suva® Suva®

MO79 MO79 MO79 408A 408A 408ASat. Liq. Sat. Vap. Av. Coil Sat. Liq. Sat. Vap Av. Coil

4.4 –4 –3 –3 –1 –1 –1

4.6 –3 –1 –2 0 0 04.8 –2 0 –1 1 2 25 –1 1 0 2 3 3

5.2 0 2 1 3 4 45.4 1 3 2 4 5 5

5.6 2 4 3 5 6 65.8 3 5 4 6 7 76 4 6 5 7 8 8

6.2 5 6 6 8 9 96.4 6 7 7 9 9 9

6.6 7 8 7 10 10 106.8 7 9 8 11 11 117 8 10 9 12 12 12

7.2 9 11 10 13 13 137.4 10 12 11 14 14 14

7.6 11 12 12 14 15 157.8 12 13 12 15 15 158 12 14 13 16 16 16

8.2 13 15 14 17 17 178.4 14 15 15 18 18 18

8.6 15 16 15 18 18 188.8 15 17 16 19 19 199 16 18 17 20 20 20

9.5 18 19 19 22 22 2210 19 21 20 23 24 23

10.5 21 23 22 25 25 2511 23 24 23 27 27 27

11.5 24 26 25 28 28 2812 26 27 26 30 30 30

12.5 27 28 28 31 31 31

13 29 30 29 33 33 3313.5 30 31 31 34 34 3414 31 33 32 35 36 35

14.5 33 34 33 37 37 3715 34 35 34 38 38 38

15.5 35 36 36 39 39 3916 36 37 37 40 41 41

16.5 37 39 38 42 42 4217 39 40 39 43 43 43

17.5 40 41 40 44 44 44

18 41 42 41 45 45 4518.5 42 43 43 46 47 4619 43 44 44 47 48 48

19.5 44 45 45 49 49 4920 45 46 46 50 50 50

20.5 46 47 47 51 51 5121 47 48 48 52 52 52

19

Pressure Temperature ( C)

bar (g)ISCEON®ISCEON®ISCEON® Suva® Suva® Suva®

MO79 MO79 MO79 408A 408A 408ASat. Liq. Sat. Vap. Av. Coil Sat. Liq. Sat. Vap Av. Coil

21.5 48 49 49 53 53 5322 49 50 50 54 54 54

22.5 50 51 51 55 55 55

23 51 52 51 56 56 5623.5 52 53 52 56 57 5724 53 54 53 57 58 58

24.5 54 55 54 58 59 5825 55 55 55 59 59 59

25.5 55 56 56 60 60 6026 56 57 57 61 61 61

26.5 57 58 58 62 62 6227 58 59 58 63 63 63

27.5 59 60 59 64 64 64

28 60 60 60 64 65 6428.5 60 61 61 65 65 6529 61 62 61 66 66 66

29.5 62 63 62 67 67 6730 63 63 63 68 68 68

30.5 63 64 64 68 68 6831 64 65 64 69 69 69

31.5 65 65 65 70 70 7032 66 66 66 71 71 71

32.5 67 67 67 71 71 71

33 72 72 7233.5 73 73 7334 73 74 74

Note: Saturated Liquid Temperature = Bubble PointSaturated Vapor Temperature = Dew Point

20

For more information and to find the location of

your nearest DuPont ISCEON® refrigerants

supplier please contact: www.isceon.com/uk

Europe, Middle East, Africa Regional OfficeDu Pont de Nemours International S.A.2 Chemin du PavillonP.O. Box 50CH-1218 Le Grand-SaconnexGeneva, SwitzerlandPhone: (+41) 22 717 5111Fax: (+41) 22 717 6169

Czech RepublicDu Pont CZ s.r.o.Pekarska 628/14155 00 Praha 5 JinonicePhone: (+420) 257 414 111Fax: (+420) 257 414 150

GermanyDu Pont de Nemours (Deutschland) GmbHHugenottenallee 173-175D- 63263 Neu-IsenburgPhone: (+49) 6102 18 1312Fax: (+49) 6012 18 1318

HungaryDu Pont Hungary Ltd.Neumann Janos street nr.l.II. floorH-2040 BudaorsPhone: (+36) 23 509 400Fax: (+36) 23 509 432

PolandDu Pont Poland Sp z.o.o.UI Powzakowska 44cPL-01-797 WarszawaPhone: (+48) 22 320 0900Fax: (+48) 22 320 0901

RussiaDu Pont Russia LLCUl. Krylatskaya, 17/3121614 MoscowPhone: +7 (495) 797 22 00/06Fax: +7 (495) 797 22 01

SpainDu Pont Iberica SAAv. Diagonal 56108029 BarcelonaPhone: (+34) 93 227 6171Fax: (+34) 93 227 6215

TurkeyDu Pont Products SABuyukdere Caddesi, Ozsezen Is MerkeziNo: 122, Kat: 1-3Esentepe 80280IstanbulPhone: (+90) 212 340 0 400Fax: (+90) 212 340 0 4

UkraineDu Pont de Nemours International S.A.Representative office – UkraineBusiness center “Podil Plaza“30/A, Spaska St. – Kyiv, 04070Phone: (+38) 044 495 26 70Fax: (+38) 044 495 26 71

United KingdomDu Pont (UK) LimitedWedgwood WayStevenageHertfordshire. SG1 4QNPhone: (+44) 438 734000Fax: (+44) 1438 734065

21

Reorder N°: K-10921 (MO79-EU) Revised 11/08Printed in Switzerland

This information corresponds to our current knowledge on the subject. It is offered solely to providepossible suggestions for your own experimentations. It is not intended, however, to substitute for anytesting you may need to conduct to determine for yourself the suitability of our products for your particularpurposes. This information may be subject to revision as new knowledge and experience becomesavailable. Since we cannot anticipate all variations in actual end-use conditions, DuPont makes nowarranties and assumes no liability in connection with any use of this information. Nothing in this publicationis to be considered as a license to operate under or a recommendation to infringe any patent right.The DuPont Oval, DuPont™, The miracles of science™, ISCEON® are registered trademarks or trademarksof DuPont or its affiliates